In a typical automotive fueling station, fuel is delivered to an above-ground dispensing pump through a network of underground tanks, pipes, fittings, sumps and dispensers. The sumps used in these networks include sumps located beneath the above-ground dispensing units. These sumps preferably fit fully beneath the housings for the above-ground dispensing units and function to prevent ground contamination from any drippage of components in the above-ground dispensing units.
In order to reduce the risk of soil contamination, it is desirable, if not imperative, for sumps located beneath the above-ground dispensing units to receive any and all fuel that may leak or drip from the dispensing units. For this reason, the openings of such sumps are large enough to completely cover the potential drip area beneath the dispensing units. It also is economically desirable to avoid making the sumps too large. Thus, it is common to have properly designed sumps with openings that are sized and shaped to match the footprint of the dispensing unit housing, i.e., the size and shape of the opening of the sump are sized and shaped to correspond to the area where drippage may occur.
It also is desirable to supply components in above-ground dispensing units with electrical power from beneath the units. This has been achieved in the prior art by passing electrical conduits through the sidewalls of the sumps, and directing the electrical conduits out of the sump through the top opening used to collect drippage. While this practice has the advantage of directing the electrical or other auxiliary communication lines to the dispensing unit under the housing, the passage of the communications lines through the wall of the sump creates a potential leak path, such as by leakage of collected fuel out of the sump and/or leakage of groundwater into the sump. This problem has been partially alleviated through the use of seals at the entry location for such lines into the sump. Nevertheless, the installation and use of such seals adds to cost. Furthermore, such seals are prone to deterioration over time, and leakage sometimes occurs despite the use of high quality seals.